POLICE have cast doubts over the truth of the story given by "Forest Boy" after his refusal to co-operate in the investigation to discover his identity.

The account from the English-speaking teenager who claims to have lived in the forest for five years with his father before burying him in a shallow grave and walking north to Berlin is riddled with inconsistencies, police say.

"He just doesn't look like a boy who lived in the forest for any amount of time," admitted Berlin police spokesman Thomas Neuendorf.

"Maybe he is telling us a story that isn't true and that is why he doesn't want to go public."

The 17-year-old claims to remember only that his name is Ray, and that he and his father had been living out in the woods since the death of his mother five years ago. He claims his parents' names were Ray and Doreen and that he was told he had no other relatives.

"The tent he had with him was used, yes, but not so well used as you'd expect for such a long time in the forest," Mr Neuendorf revealed.

"And he was clean and wearing clean clothes. His fingernails were well kept and his hands soft. Such things raise questions."

Investigators have become frustrated at a lack of progress in the case after requests to Interpol to help trace him turned up nothing.

Police forces in the south of Germany and in the neighbouring Czech Republic and Austria were asked to report if a corpse had been found in the woods but no such discoveries have been made.

"We haven't found a body," said Mr Neuendorf. "He hasn't expanded on his original story and can't tell us any facts or anything that we can usefully check. He can't name or describe a single landmark, town or place that may lead us to retrace his steps but just keeps repeating the same vague story."

Mr Neuendorf continued: "He said he walked for two weeks but can't tell us anything about the journey or why he chose to go the City Hall."

It is still not known whether the boy, who reportedly speaks only a few words of German, is a native English speaker. "An interpreter said he spoke English very well but that it may be learnt English and without further studies we can't tell," the police spokesman said.

Police had hoped that with the appointment of a legal guardian to represent the boy, they could proceed with a public appeal and could expand the investigation to include further linguistic studies, DNA sampling and checking against dental records.

"With a public appeal someone might have recognised him and helped fill in the gaps," said the police spokesman.

But the boy has told his legal guardian, a female social worker appointed on Monday, that he had no wish to discover his true identity telling her: "I just want to get on with my life."

That decision has added to police suspicions over the truth of his story. "How can it be that someone who doesn't know who he is or how he has spent the last months or years isn't interested in finding out?" asked Mr Neuendorf.

Angelika Schöttler, the councillor in charge of youth welfare services in the Templehof-Schöneberg district of Berlin, where the boy is being cared for said: “We have decided that we will not further investigate the matter, or make more information about the boy public. Our job is to protect the boy. We may at some point seek further clarification from the boy, but that is not yet decided.”

“We have decided in cases like this we cannot give out more information. We serve to protect youth. This is the thoughtful and appropriate thing to do at this time. We have different interests than other agencies.”